CIESC Journal ›› 2015, Vol. 66 ›› Issue (9): 3421-3427.DOI: 10.11949/j.issn.0438-1157.20150902

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CeO2 nanoclusters stabilized in aerogel matrix as catalysts for Cl2 production from HCl oxidation

XU Xihua1, FEI Zhaoyang1, CHEN Xian2, TANG Jihai1, CUI Mifen2, QIAO Xu1,2   

  1. 1 State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009, Jiangsu, China;
    2 College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, Jiangsu, China
  • Received:2015-06-11 Revised:2015-06-30 Online:2015-09-05 Published:2015-09-05
  • Supported by:

    supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (2011BAE18B01), the National Natural Science Foundation of China (21306089), the Higher Education Natural Science Foundation of Jiangsu Province (13KJB530006) and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

气凝胶骨架镶嵌的CeO2纳米团簇催化氧化HCl制Cl2

徐希化1, 费兆阳1, 陈献2, 汤吉海1, 崔咪芬2, 乔旭1,2   

  1. 1 南京工业大学材料化学工程国家重点实验室, 江苏 南京 210009;
    2 南京工业大学化工学院, 江苏 南京 210009
  • 通讯作者: 费兆阳, 乔旭
  • 基金资助:

    国家科技支撑计划项目(2011BAE18B01);国家自然科学基金项目(21306089);江苏省高校自然科学基金项目(13KJB530006);江苏高校优势学科建设工程资助项目。

Abstract:

CeO2 nanoclusters inserted into aerogel matrix (CeO2@MxOy, MxOy= SiO2, ZrO2, Al2O3) prepared by a single-step sol-gel method were used as catalysts for recycling Cl2 from HCl oxidation. Due to their remarkable quantum-size effects, the properties of CeO2 nanoclusters were significantly different from crystal phase CeO2. The CeO2 nanoclusters could be completely reduced at the temperature range for reduction of the surface oxygen species of crystal phase CeO2. The unique properties of CeO2 nanoclusters resulted in the high activity of CeO2@MxOy in the process of HCl oxidation reaction. 40CeO2@SiO2 exhibited the highest activity and the STY (space time yield of Cl2) reached to 2.10 g·(g cat)-1·h-1 at 430℃ with VO2/VHCl of 1 and contact time of 0.1598 h. Kinetic studies showed that both O2 and HCl competed for the active sites rendering desorption of surface Cl as the rate-determining step.

Key words: CeO2, nanoclusters, aerogel, chlorine recycle, catalytic oxidation, kinetics

摘要:

采用一步溶胶-凝胶法制备了镶嵌于气凝胶骨架内的CeO2纳米团簇催化材料(CeO2@MxOy, MxOy= SiO2、ZrO2、Al2O3)用于HCl催化氧化反应。镶嵌于气凝胶骨架内的CeO2纳米团簇显著的量子尺寸效应导致其表现出不同于晶相CeO2的特性,H2-TPR测试结果显示在晶相CeO2表面氧物种还原温区内CeO2纳米团簇即可被充分还原。优异的氧化还原性能导致CeO2@MxOy在HCl氧化过程具有良好的催化活性,其中,40CeO2@SiO2的活性最高,在接触时间为0.1598 h,VO2/VHCl为1,430℃时,Cl2空时产率可以达到2.10 g·(g cat)-1·h-1。催化剂表面的HCl氧化反应同时受O2分压和HCl分压的影响,这表明Cl2从催化剂表面的脱附是该反应的决速步骤。

关键词: 氧化铈, 纳米团簇, 气凝胶, 氯循环, 催化氧化, 动力学

CLC Number: